Power rating -- looking for regulatory guidance

Wow, a lot of words to fly solo...
First...get an instructor....since you’re a smart rich guy....you might as well get your Student Medical Certificate from a AME of choice.
Start your lessons and one day the instructor hops out.
The instructor will define your limitations including how often he will fly with you to monitor your proficiency.
Your instructor has the answers to what you want to do. Your question reads to me that you have something out of the ordinary in mind.
That you’re not interested in ‘rating collecting’. If so, explain this to your instructor so he can custom tailor your lessons..
An example would be you want to race a single seat aircraft. Since you have all the skillset of a pilot, this would be an easy transition.
I’m being very basic to answer a basic question.
R